Side airbag device

ABSTRACT

A side airbag device includes: an inflator; a cushion that is expandable from the side of a seat toward a front of a vehicle; a vent hole that is provided at a predetermined position of the cushion and that discharges the gas; a patch that openably covers the vent hole from an inside of the cushion; a tether that is connected to the patch and a predetermined position (a tether cutter) of the side of the seat, the tether pulling the patch toward a rear of the vehicle so as to open the vent hole when the cushion is expanded and deployed; and a tether cutter that is configured to cut the tether in response to information relating to a state of the vehicle.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a 371 U.S. National Stage of InternationalApplication No. PCT/JP2017/017883, filed May 11, 2017, which claimspriority to Japanese Patent Application No. 2016-101614, filed May 20,2016. The disclosures of the above applications are incorporated hereinby reference.

TECHNICAL FIELD

The present invention relates to a side airbag device that has aninflator that supplies a gas and an airbag cushion that is provided at aside part of a vehicle seat and that is expandable from the side part toa front side of the vehicle by the gas.

BACKGROUND ART

In the recent years, an airbag device is mostly equipped as the standardequipment on a vehicle. The airbag device is a safety device beingoperated in an emergency such as a vehicle collision and protects anoccupant by receiving the occupant by expanding and deploying an airbagcushion with a gas pressure. There are various kinds of airbag devicesaccording to the installation positions or the use. For instance, afront airbag device is provided at a center of a steering wheel so thata driver can be protected from a collision in front and rear directions.In addition, in order to protect occupants from an impact in a vehiclewidth direction by such as a side collision, a curtain airbag device isprovided near a ceiling above a side window and a side airbag device isprovided at a side part of a seat.

A shape of an airbag cushion is set in consideration of such as apositional relationship with an occupant and a surrounding structure.For instance, a vehicle airbag of Patent Document 1 has an airbag bodyfor a passenger seat in which a capacity is relatively large. In PatentDocument 1, in consideration of the positional relationship with a headof the occupant, an expansion control tether is provided inside of theairbag body. By pulling a base cloth of the airbag body from the inside,the expansion control tether suppresses the expansion and the load tothe occupant.

PRIOR ART DOCUMENT Patent Document

Patent Document 1: Japanese Patent Publication Number 2000-142290.

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

With respect to an airbag cushion of a side airbag device, a measure forsuppressing the load that an occupant receives during the restraint isrequested as well. For instance, the load that can be given to theoccupant by the airbag cushion increases in proportion to such as acollision speed at a vehicle collision. An internal pressure of theairbag cushion corresponds to an output of an inflator that is an originof a supply of the gas, however, it is not an efficient means to modifythe output itself of the inflator according to the collision speed fromthe point of the complication of the structure and the cost.

The present invention attempts to solve these problems. An object of thepresent invention is to provide a side airbag device that can adjust aninternal pressure of an airbag cushion according to various conditionssuch as a collision speed, a collision angle, a physique of an occupant,and collision energy at a vehicle collision.

Means for Solving the Problems

In order to solve the above problems, a side airbag device according tothe present invention includes the following most essential features: aninflator that supplies a gas; an airbag cushion that is disposed at aside of a seat of a vehicle and that is expandable from the side towarda front of the vehicle by the gas; a vent hole that is provided at apredetermined position of the airbag cushion and that discharges thegas; a patch that openably covers the vent hole from an inside of theairbag cushion; a tether that is connected to the patch and apredetermined position of the side of the seat, the tether pulling thepatch toward a rear of the vehicle so as to open the vent hole when theairbag cushion is expanded and deployed; and a tether cutter that isconfigured to cut the tether in response to information relating to astate of the vehicle.

According to the configuration explained above, it becomes possible toadjust the rigidity of the airbag cushion in response to the informationrelating to the state of the vehicle. For instance, when a sensor for aside collision and a weight detection sensor of the occupant that isformed in the seat are utilized, the information regarding the collisionspeed in a horizontal (sidewise) direction and the physique of theoccupant can be obtained, and a tether can be cut when a predeterminedcondition is met. For instance, when the collision speed in thehorizontal direction is lower, because a moving speed in the horizontaldirection of the occupant also becomes low, an injury value of theairbag cushion for the occupant are not so high although the airbagcushion is hard and expanded with a high internal pressure. Further,when the physique of the occupant is equal to or more than apredetermined value (for instance, is equal to or more than a pertinentvalue for an adult male), a tolerance for the collision energy isexpected to be high. Accordingly, when the collision speed in thehorizontal direction is lower than the predetermined value and thephysique of the occupant is equal to or more than the predeterminedvalue, the tether is cut by a tether cutter so that the vent hole isclosed, and as a result, a pressure of the airbag cushion is kept highby preventing the gas from discharging. As a result, the occupant can besufficiently restrained.

On the other hand, when the collision speed in the horizontal directionis high, the moving speed of the occupant in the horizontal directionalso becomes high, therefore, the injury value for the occupant alsotends to be high. Further, when the physique of the occupant is lessthan the predetermined value (for instance, is less than the pertinentvalue for the adult male), the tolerance for collision energy is alsoexpected to be low. Accordingly, when the collision speed is equal to ormore than the predetermined value and when the physique of the occupantis less than the predetermined value, the tether cutter does not move,the vent hole is open by pulling the patch by the tether, and a cushioninternal pressure of the airbag cushion is suppressed by discharging thegas from the vent hole. Therefore, when the occupant who has the highermoving speed or who is a petite occupant is restrained, the injury valuefor the occupant can be suppressed.

The side airbag device may further have sewing parts in which the patchand at least both-side areas of the airbag cushion that sandwiches thevent hole are connected by sewing. The sewing parts may be linearlyprovided in parallel with each other at the both-side areas of theairbag cushion that sandwiches the vent hole. According to theseconfigurations, the patch can be suitably connected to the airbagcushion.

The vent hole may be provided in an edge of a vehicle front side of theairbag cushion. Further, the vent hole may be provided in a side surfaceof the airbag cushion in a vehicle width direction and is close to avehicle front side of the airbag cushion. According to the vent holehaving these configurations, the gas can also be suitably discharged.

An intermediate portion of the tether in a longitudinal direction may beconnected to the patch, and a front end of the tether may be connectedto an inner position of the airbag cushion. The inner position islocated further to a vehicle front side than the vent hole. According tothis configuration, the vent hole can be suitably opened by pulling thepatch by the tether.

The tether may be connected to the patch at a center of the vent hole.According to this configuration, the vent hole can also be suitablyopened by pulling the patch by the tether.

The airbag cushion may have an outer peripheral sewing part in which abase cloth at an edge of the airbag cushion is sewed, and one end of thepatch and one end of the tether may be sewed together with the outerperipheral sewing part. According to this configuration, the patch andthe tether can be connected to the airbag cushion in a concise manner.Further, by the tether, the expansion in the vehicle longitudinaldirection of the cushion is limited and it becomes possible that thecushion is further thickly expanded in the vehicle width direction sothat an occupant restraint force is increased.

The patch may have a slit that extends in a direction crossing alongitudinal direction of the tether. By opening the slit, the gas canbe suitably discharged. Further, the tether may pass through the patchvia the slit in a vehicle front and rear direction. According to thisconfiguration, the slit can be suitably opened.

The inflator is disposed inside of the airbag cushion at a vehicle rearside. The side airbag device further including: an inner bag that isprovided inside of the airbag cushion, a base cloth of the inner bagsurrounds the inflator; and an inner vent that is disposed at a vehiclefront side of the inner gag and through which the gas is passable.Further, the tether may pass through the inner vent so as to beconnected to the patch and the predetermined position of the side of theseat.

According to the configuration explained above, because the inner bagtakes the initiative to receive the gas that is supplied from theinflator at first, it can be prevented that the rigidity at the partthat contacts the occupant is rapidly increased.

It is preferred that the inner vent is located on a linear lineconnecting between the patch and the predetermined position of the sideof the seat. According to this configuration, the tether can bridge overat the shortest distance.

Effects of the Invention

According to the present invention, it becomes possible to provide aside airbag device that can adjust an internal pressure of an airbagcushion according to a collision speed at a vehicle collision.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram that exemplarily shows a side airbag deviceaccording to a first embodiment of the present invention.

FIG. 2A is a side view of the side airbag device of FIG. 1, the sideairbag device shown operatively associated with a sensor and controlunit.

FIG. 2B is a cross-sectional view taken along the line A-A of FIG. 2Abefore the tether is cut.

FIG. 2C is a cross-sectional similar to FIG. 2B shown after the tetheris cut.

FIG. 3A is a side view similar to FIG. 2A illustrating a side airbagdevice according to a second embodiment of the present invention.

FIG. 3B is a cross-sectional view taken along the line B-B of FIG. 3Abefore the tether is cut.

FIG. 3C is a cross-sectional similar to FIG. 3B shown after the tetheris cut.

FIG. 4A is another side view similar to FIG. 3A illustrating a sideairbag device according to a third embodiment of the present invention.

FIG. 4B is a cross-sectional view taken along the line C-C of FIG. 4Abefore the tether is cut.

FIG. 4C is a cross-sectional similar to FIG. 4B shown after the tetheris cut.

FIG. 5 is a diagram that shows a variation of a sewing part exemplarilyshown in, for example, FIG. 2B.

EXPLANATION OF REFERENCE SIGNS

L1—Length of Tether, L2—Distance between Vent Hole and Tether Cutter,L3—Length of Tether in the second embodiment, L4—Distance between FrontEnd of Cushion and Tether Cutter, L5—Length of Tether in the thirdembodiment, 100—Side Airbag Device in the first embodiment, 102—Seat,104—Cushion, 105—Outer Peripheral Sewing Part, 106—Main Panel, 106a—Main Panel on the left side in the Vehicle Width Direction, 106 b—MainPanel on the right side in the Vehicle Width Direction, 108—Seat Back,110—Inflator, 112—Stud Bolt, 116—Vent Hole, 118—Inner Bag, 120 a—UpperInner Vent, 120 b—Lower Inner Vent, 122—Patch, 122 a—Left Edge of Patch,122 b—Right Edge of Patch, 122 c—Upper Edge of Patch, 122 d—Lower edgeof Patch, 124 a—Left Sewing Part, 124 b—Right Sewing Part, 126—Tether,128—Tether Cutter, 130—Connector, 132—Sensor, 134—Control Unit, 200—SideAirbag Device in the second embodiment, 202—Vent Hole, 204—Patch,206—Tether, 208—Front End of Tether, 300—Side Airbag Device in the thirdembodiment, 302—Patch, 302 a—Upper End of Patch, 302 b—Lower End ofPatch, 304—Slit, 306—Tether, 308—Front End of Tether, 400 a—Upper SewingPart of Variation, 400 b—Lower Sewing Part of Variation

MODE FOR CARRYING OUT THE INVENTION

Preferred embodiments of the present invention will be explained indetail with reference to the attached drawings below. The dimensions,materials, other concrete numerical values, and other that are disclosedin the embodiments are merely examples for facilitating understanding ofthe invention, and unless otherwise stated, they are not limited thepresent invention. Further, in this specification and the drawings, withrespect to the elements having substantially the same functions andconfigurations, redundant explanations are omitted by accompanying thesame reference numerals. Further, the elements that are not directlyrelated to the present invention are not shown in the drawings.

First Embodiment

FIG. 1 is a diagram that exemplarily shows a side airbag device 100according to a first embodiment of the present invention. FIG. 1Aexemplarily shows the side airbag device 100 and a seat 102 in which theside airbag device 100 is utilized viewed from a left side in a vehiclewidth direction. In the following disclosures, with respect to FIG. 1and all other diagrams according to the present invention, the vehiclefront and rear (longitudinal) directions respectively denote the arrowsF (Forward) and B (Back), the crosswise directions that correspond to aninterior side and an exterior side in the vehicle width directionrespectively denote the arrows L (Left) and R (Right), and the vehiclevertical directions respectively denote the arrows U (Up) and D (Down).

As shown in FIG. 1, the side airbag device 100 has a configuration inwhich an airbag cushion (a cushion 104) is expanded and deployed from aninside of a seat back 108 of the seat 102. The cushion 104 is theportion in which the occupant is restrained in an emergency and ishoused in a side part of the seat back 108 in the vehicle widthdirection in the state of being wound or folded prior to its operation.Thereafter, by detecting the impact of the vehicle, the expansion andthe deployment are performed from the side part toward the vehicle frontside by utilizing a gas.

In the present embodiment, the cushion 104 is provided on the left sideof the seat back 108, however, it is possible that the cushion 104 isprovided on the right side. That is, the cushion 104 can be providedeither at the side part on the door side (near side) or at the side partof the interior side (far side) of the seat back 108.

The cushion 104 is formed in a flat shape as a whole. An outside surfaceof the cushion 104 is configured with a main panel 106 (a main panel 106a at the left side in the vehicle width direction, a vehicle main panel106 b at the right side in the vehicle width direction). The main panel106 is obtained from a base cloth and is formed in a bag shape as awhole by a sewing or an adhesion. Further, the cushion 104 can also beformed by the spinning and weaving by the utilization of OPW (One-PieceWoven).

An inflator 110 is installed at a vehicle rear side of an inside of thecushion 104. The inflator 110 is a gas generator and a cylinder type (acylindrical type) is adopted in the present embodiment. The inflator iselectrically connected to the vehicle side and is operated by receivinga signal caused by the detection of the impact from the vehicle side soas to supply the gas to the cushion 104. The inflator 110 has a studbolt 112 that is fastened to the seat back 108. Because the stud bolt112 is fastened to the seat back 108 by penetrating through the cushion104, the cushion 104 is also attached to the seat back 108.

There are some kinds of the inflators, such as a model in which a gasgenerating agent is charged and a gas is generated by burning the gasgenerating agent, a model in which a compressed gas is filled and a gasis supplied without generating heat, or a hybrid model in which acombustion gas and a compressed gas are used as an inflator spreadthrough the market at the present time. Any kinds of the inflators canbe utilized as the inflator 110.

A vent hole 116 is provided in a slightly lower part of an edge at avehicle front side of the cushion 104. The vent hole 116 discharges thegas, which is supplied from the inflator 110, from the inside of thecushion 104.

The side airbag device 100 according to the present embodiment canadjust the internal pressure of the cushion 104 according to a state ofthe vehicle by utilizing the vent hole 116. In the present embodiment,as an example of the state of the vehicle, the internal pressure of thecushion 104 is adjusted according to the collision speed or the physiqueof the occupant at the vehicle collision. For instance, when thecollision speed in a horizontal (sidewise) direction is high at the timeof the side collision, the moving speed in the horizontal direction ofthe occupant becomes high and the load that the occupant receives tendsto be increased during the restraint of the occupant by the cushion 104.Similarly, even for the petite occupant, the tolerance for collisionenergy is expected to be low. Accordingly, in the present embodiment,when the predetermined conditions are met, such as, when the collisionspeed in the horizontal direction is higher than the predetermined valueor when the physique of the occupant is less than the predeterminedvalue, a configuration, in which the gas is discharged from the venthole 116, is adopted so that the internal pressure of the cushion 104 isreduced.

FIG. 2 is a diagram that exemplarily shows each cushion 104 shown inFIG. 1 viewed from each of directions. FIG. 2A is a diagram thatexemplarily shows the cushion 104 while transmitting the inside viewedfrom the left side in the vehicle width direction.

An inner bag 118 is provided inside of the cushion 104. The inner bag118 is provided to surround the inflator 110 inside of the cushion 104.Because the inner bag 118 receives the gas that is supplied from theinflator 110 before the main panel 106 receives, it is possible toprevent the rigidity of the main panel 106 that contacts with theoccupant from being rapidly increased.

The inner bag 118 is provided in a bag shape enclosing the inflator 110therein. The inner bag 118 can also be provided in a manner in which,for instance, a base cloth that is fitted to the shape of the vehiclerear side of the cushion 104 is folded and arranged in the bag shape anda part thereof is overlapped and sewed together with the outercircumference of the main panels 106 a and 106 b (refer to FIG. 1).

As the portions for supplying the gas to the vehicle front side of thecushion 104, two openings, which are an inner vent 120 a at the topportion and an inner vent 120 b at the bottom portion of the vehiclefront side, are provided in the inner bag 118. The gas that is suppliedfrom the inflator 110 respectively passes through the inner vents 120 aand 120 b and flows toward the vehicle front side. As explained above,in the present embodiment, the configuration in which the inner bag 118receives the gas from the inflator 110 first, and subsequently, the gasis supplied to the entirety of the cushion 104 from the inner bag 118 isadopted.

A patch 122 is provided inside of the vent hole 116. The patch 122openably covers the vent hole 116 from the inside of the cushion 104.For instance, the patch 112 uses the same base cloth as, for example,the main panel 106 and is provided by being connected to both-side partsin the vehicle width direction sandwiching the vent hole 116 of thecushion 104 by linear sewing parts 124 a and 124 b (refer to FIG. 2B).For instance, by providing the sewing parts 124 a and 124 b at bothsides of the vent hole 116 in parallel, because right and left edges 122a and 122 b of the patch 122 are connected to the cushion 104 andbecause upper and lower edges 122 c and 122 d of the patch 122 canbecome separated from the cushion 104, the patch 122, which can beopened and closed, can be suitably realized.

A string-like tether 126 is connected to the patch 122. The tether 126is the portion to make the vent hole 116 be opened by pulling the patch122 according to the detection result of a sensor 132 at the time of theexpansion and the deployment of the cushion 104. The tether 126penetrates the inner bag 118 through the inner vent 120 b so as to beconnected to a tether cutter 128 at the vehicle rear side. The innervent 120 b is provided on the path linearly connecting the patch 122 andthe tether cutter 128 so that the tether 126 can bridge over the patch122 and the tether cutter 128 at the shortest distance.

The tether cutter 128 is small, has a cylindrical shape, and is providedat a predetermined position of the side part of the seat 102 (refer toFIG. 1) together with such as the cushion 104. A cylinder (not shown)having a cutting edge and a micro gas generator (not shown) are providedinside of the tether cutter 128. The tether cutter 128 is electricallyconnected to such as a power source and a sensor 132 of the vehicle sideby a connector 130, and the cutting edge moves according to thedetection result of the sensor 132. The tether 126 is passed through ahole (not shown) of the tether cutter 128 and is fastened to the tethercutter 128 in a state in which the tether 126 can be cut by the tethercutter 128.

The sensor 132 is provided at various places of the vehicle, measuresand detects the states of the vehicle, and obtains the variouspredetermined information from the vehicle. As the sensor 132, varioussensors can be utilized, for instance, a sensor for the side collisionthat detects the collision speed in the vehicle horizontal direction bybeing provided at the side part of the vehicle, a sensor for the frontcollision that detects the collision speed in the vehicle longitudinaldirection by being provided at the front part of the vehicle, and aweight detection sensor that detects the weight or the physique of theoccupant by being provided at the seat.

A control unit 134 processes each information that is obtained by thesensor 132 and controls the movability of the tether cutter 128according to the predetermined condition (for instance, whether thecollision speed in the horizontal direction is higher or lower than thepredetermined value). The control unit 134 can also be utilized bymultiply processing the detection results of a plurality of sensors, andas a result, the various information such as the collision speed, thecollision angle, the collision energy, and the physique of the occupantat the vehicle collision are calculated, and it is possible to decidewhether a movability signal is sent to the tether cutter 128 or notsubject to the above calculated information.

FIG. 2B is a cross sectional view along the A-A line of the cushion 104shown in FIG. 2A. FIG. 2B shows a state of the cushion 104 after themovement of the inflator 110. In the present embodiment, when the injuryvalue for the occupant is expected to become high during the restraint,the control unit 134 does not move the tether cutter 128. In this case,because the patch 122 is pulled toward the vehicle rear side by thetether 126, a gap between the patch 122 and the vent hole 116 is widenedso that the gas is discharged from the vent hole 116. As a result, theinternal pressure of the cushion 104 is suppressed and the rigidity ofthe main panel 106 is also reduced. Therefore, the load that is given tothe occupant who contacts with the main panel 106 can be suppressed.

The tether 126 is connected to the patch 122 at the center of the venthole 116 so as to efficiently separate the patch 122 from the vent hole116. Further, the tether 126 has a length L1 that is shorter than adistance L2 between the vent hole 116 and the tether cutter 128 at thetime of the expansion and the deployment of the cushion 104 (L1>L2). Thetether 126 with this length L1 can open the vent hole by suitablypulling the patch 112.

Unlike FIG. 2B, FIG. 2C shows a state of the cushion 104 when the injuryvalue for the occupant is expected to become low during the restraint.In this case, an operation signal from the control unit 134 (refer toFIG. 2A) is sent to the tether cutter 128 through the connector 130 sothat the cutting edge moves and the tether 126 is cut. As a result, thepatch 122 covers in such a way as to stick the vent hole 116 by the gaspressure and keeps the vent hole 116 closed so as to prevent the gasfrom discharging from the cushion 104. As a result, the pressure of thecushion 104 can be kept high. Therefore, the cushion 104 cansufficiently restrain the occupant by the high internal pressure.

The example of the control of the tether cutter 128 with a focus on thecontrol unit 134 shown in FIG. 2A will be explained in detail. Thecontrol unit 134 can control the tether cutter 126 based on theinformation regarding the state of the vehicle such as the collisionspeed or the physique of the occupant that is obtained by the sensor132.

For instance, the control unit 134 may control the tether cutter 128subject to the collision speed. In the side collision, when thecollision speed in the vehicle horizontal direction is high, the movingspeed in the horizontal direction of the occupant also becomes high andthere is a possibility that the injury value becomes high during therestraint by the cushion 104. Accordingly, when the collision speed thatis obtained by the sensor for the side collision is equal to or higherthan the predetermined threshold value (for instance: 30 km/h), thecontrol unit 134 can determine not to send the movability signal to thetether cutter 128. As a result, as exemplarily shown in FIG. 2B, thepatch 122 is pulled by the tether 126 and the gas is discharged from thevent hole 116 so that the internal pressure of the cushion 104 isreduced. On the contrary, the collision speed is less than the thresholdvalue, the control unit 134 determines to send the movability signal tothe tether cutter 128. As a result, as shown in FIG. 2C, the tether 126is cut and the vent hole 116 is closed by the patch 122, and theinternal pressure of the cushion 104 is kept high.

As another example for the control, the control unit 134 can alsocontrol the tether cutter 128 subject to the physique of the occupant.In case of the petite occupant, because the tolerance for collisionenergy is expected to be low, there is a possibility that the injuryvalue becomes high during the restraint by the cushion 104. Accordingly,when the information regarding the physique of the occupant that isobtained by the weight detection sensor at the seat is less than thepredetermined threshold value (for instance: the physique of the adultmale), the control unit 134 can determine not to send the movabilitysignal to the tether cutter 126. As a result, as exemplarily shown inFIG. 2B, the patch 122 is pulled by the tether 126 and the gas isdischarged from the vent hole 116, and the internal pressure of thecushion 104 is reduced. On the contrary, when the physique of theoccupant is equal to or more than the threshold value, because thetolerance for collision energy is expected to be high, the control unit134 determines to send the movability signal to the tether cutter 128.As a result, as shown in FIG. 2C, the tether 126 is cut and the venthole 116 is closed by the patch 122 so that the internal pressure of thecushion 104 is kept high.

Further, as the concrete example for the judgement of the physique ofthe occupant, for instance, it is possible to utilize a dummy doll AM50(corresponds to a male of 50th percentile, the height is 175 cm and theweight is 78 kg) shaped like the physique that conforms the 50% of theaverage United States adult males for testing as the threshold value.

As yet another example for the control, the control unit 134 can controlthe tether cutter 128 by modifying the threshold value according to thephysique of the occupant. Even by the same collision speed, if thephysiques of the occupant are different, the injury values fluctuate.Accordingly, for instance, when the physique of the occupant isdetermined to correspond to the adult male, it is also possible that thecontrol unit 134 considers that the tolerance to the impact energy ishigh so as to increase the threshold value of the collision speed anddetermines to move the tether cutter 128 so as to maintain the internalpressure of the cushion main body 120 high even though the collisionspeed is high. Further, for instance, when the physique of the occupantis determined to correspond to the petite woman, it is also possiblethat the control unit 134 considers that the tolerance to the impactenergy is low so as to decrease the threshold value of the collisionspeed and determines not to move the tether cutter 126 so as to suppressthe internal pressure of the cushion main body 120 low even though thecollision speed is low.

Further, in the present embodiment, the information regarding thecollision angle (an approach angle of an object with respect to thevehicle longitudinal direction) can also be obtained by utilizing suchas the sensor for the front collision and the other collision detectionsensor. For instance, when the vehicle is collided at the angle of beingnot the mere longitudinal direction and horizontal direction such as anoblique collision and an offset collision, there is a case in which asmaller value than an actual value of the collision speed that isactually applied to the occupant is obtained when the collision speedfor only in the longitudinal direction or the horizontal direction ismeasured. As a result, it means that in case of such as the obliquecollision, as compared with the cases of the front collision and theside collision, the higher value is relatively set even the samethreshold value. Accordingly, when the collision speed that is appliedto the occupant is calculated by also obtaining the collision angle asexplained above, it becomes possible that the tether cutter 128 iscontrolled by accurately matching the actual collision speed.

As explained above, according to the side airbag device 100, it ispossible that the choice of the presence or absence of the discharge ofthe gas is performed according to the various conditions such asaccording to the various conditions such as the collision speed, thecollision angle, the physique of the occupant, and collision energy atthe vehicle collision so as to adjust the internal pressure of thecushion 104. As a result, it is possible that the occupant isefficiently restrained without the increase of the injury value for theoccupant.

Second Embodiment

FIG. 3 is a diagram that exemplarily shows a side airbag device 200according to a second embodiment of the present invention. The sideairbag device 200 is different from the side airbag device 100exemplarily shown in FIG. 2 with respect to the configurations of a venthole 202 and a patch 204. In the following descriptions, with respect tothe elements that are already explained, the explanations thereof areomitted by accompanying the same reference numerals. Further, if thereare the elements that have different reference numerals and if theseelements have the same names with the elements that are alreadyexplained, the basic configuration and functions of these elements arethe same.

With respect to the side airbag device 200, the vent hole 202 isprovided close to the vehicle front side of the main panel 106 a at theleft side in the vehicle width direction (the outside when viewed fromthe seat 102 shown in FIG. 1) of the cushion 104. The vent hole 202 alsohas the configuration in which the gas is selectively discharged by thepatch 204 according to the circumstances.

FIG. 3B is a cross sectional view along the B-B line of the cushion 104shown in FIG. 3A. FIG. 3B shows a state of the cushion 104 after themovement of the inflator 110. In the present embodiment, when the injuryvalue for the occupant is expected to become high during the restraint,the tether cutter 128 does not move neither. As a result, because thepatch 204 is pulled toward the vehicle rear side by a tether 206, thegap between the patch 204 and the vent hole 202 is widened so that thegas is discharged from the vent hole 202. As a result, because theinternal pressure of the cushion 104 is suppressed and the rigidity ofthe main panel 106 is also reduced, even also when the occupant who hasthe higher moving speed contacts with the main panel 106, the load thatthe occupant receives can be suppressed.

The tether 206 has mostly the same configuration of the tether 126 shownin, for example, FIG. 2B, however, the tether 206 is connected to thepatch 204 at an intermediate portion thereof in the longitudinaldirection. Further, a front end 208 of the tether 206 is connected tothe inside of the cushion 104 located further to the vehicle front sidethan the vent hole 202.

A length L3 of the tether 206 can be set to be mostly the same length asa length L4 (refer to FIG. 3C) between the front end 208 of the cushion104 and the tether cutter 128 or less at the time of the expansion andthe deployment of the cushion 104. The tether 206 having thisconfiguration becomes tensed in the vehicle longitudinal direction atthe center in the vehicle width direction of the cushion 104 accordingto the expansion and the deployment of the cushion 104. Therefore,because the tether 206 pulls the patch 204 toward the center side of thecushion 104, the vent hole 202 can be suitably open.

One end of the patch 204 and one end of the tether 206 are sewedtogether with an outer peripheral sewing part 105 of the cushion 104.The outer peripheral sewing part 105 corresponds to a peripheral edge ofthe cushion 104 when the cushion 104 is viewed from the vehicle widthdirection (refer to FIG. 3A) and corresponds to the portion in which themain panels 106 a and 106 b are sewed together in the vehicle widthdirection. The patch 204 and the tether 206 can be connected to thecushion 104 by being sewed together with the outer peripheral sewingpart 105 in a concise manner.

Because the tether 206 bridges over between the outer peripheral sewingpart 105 that is the front end of the cushion 104 and the tether cutter128 at the vehicle rear side, the tether 206 limits the expansion of thecushion 104 in the vehicle longitudinal direction so that the cushion104 can be further thickly expand in the vehicle width direction.Therefore, it becomes possible that the occupant restraint ability forthe occupant who contacts in the vehicle width direction is increasedand the occupant is further suitably received.

Unlike FIG. 3B, FIG. 3C shows a state of the cushion 104 when the injuryvalue for the occupant is expected to become low during the restraint.In this case, because the tether cutter 128 is operated, the tether 206is cut. As a result, the patch 204 covers in such a way as to stick thevent hole 202 by the gas pressure and keeps the vent hole 202 closed soas to prevent the gas from discharging from the cushion 104. As aresult, the pressure of the cushion 104 can be kept high. Therefore, thecushion 104 can sufficiently restrain the occupant by the high internalpressure.

As explained above, according to the side airbag device 200, it is alsopossible that the choice of the presence or absence of the discharge ofthe gas is performed according to the various conditions such asaccording to the various conditions such as the collision speed, thecollision angle, the physique of the occupant, and collision energy atthe vehicle collision so as to adjust the internal pressure of thecushion 104. As a result, it is possible that the occupant isefficiently restrained without the increase of the injury value for theoccupant.

Third Embodiment

FIG. 4 is a diagram that exemplarily shows a side airbag device 300according to a third embodiment of the present invention. The sideairbag device 300 is different from the side airbag device 200exemplarily shown in FIG. 3 with respect to a slit 304 provided in apatch 302. The slit 304 is provided as a cut that extends in thevertical direction, i.e., in a direction crossing the longitudinaldirection of the tether 306 between the vent hole 202 and the sewingpart 124 a beside the vent hole 202.

FIG. 4B is a cross sectional view along the C-C line of the cushion 104shown in FIG. 4A. FIG. 4B exemplarily shows a state after the inflator110 moves and corresponds to a case in which the injury value for theoccupant is expected to become high during the restraint. In that case,because the tether cutter 128 does not move, the patch 302 is pulled bya tether 306 so that the vent hole 202 is opened.

The tether 306 has mostly the same configuration as the tether 206 shownin FIG. 3B, however, the tether 306 penetrates the patch 302 in thevehicle longitudinal direction through the slit 304 and an intermediateportion the tether 306 in the longitudinal direction is connected to theoutside of the patch 302 by sewing. Further, a front end 308 of thetether 306 together with the patch 302 are sewed together with the outerperipheral sewing part 105 located further to the vehicle front sidethan the vent hole 202.

In the same manner as the tether 206 shown in FIG. 3B, a length L5 ofthe tether 306 can also be set to be mostly the same length as thelength L4 (refer to FIG. 4C) between the front end (the outer peripheralsewing part 105) of the cushion 104 and the tether cutter 128 or less atthe time of the expansion and the deployment of the cushion 104. As aresult, the tether 306 becomes tensed in the vehicle longitudinaldirection at the center in the vehicle width direction of the cushion104 according to the expansion and the deployment of the cushion 104.

Because the tether 306 passes at the outside of the patch 302 throughthe slit 304, by the tension of the tether 306, part of the patch 302that is located at the vehicle front side than the slit 304 moves to thecenter side in the vehicle width direction of the cushion 104 along withthe tether 306. As a result, because the gas passes through not only aspace between the upper and lower ends 302 a and 302 b (refer to FIG.4A) of the patch 302 and the main panel 106, but also from the slit 304,the gas is efficiently discharged by the guide of the vent hole 202. Asa result, because the internal pressure of the cushion 104 is furthersuppressed and the rigidity of the main panel 106 is also furtherreduced, even also when the occupant who has the higher moving speedcontacts with the main panel 106, the load that the occupant receivescan be efficiently suppressed.

Unlike FIG. 4B, FIG. 4C shows a state of the cushion 104 when the injuryvalue for the occupant is expected to become low during the restraint.In this case, because the tether cutter 128 is operated, the tether 306is cut. As a result, the patch 302 covers in such a way as to stick thevent hole 202 by the gas pressure and keeps the vent hole 202 closed soas to prevent the gas from discharging from the cushion 104. As aresult, the pressure of the cushion 104 can be kept high. Therefore, thecushion 104 can sufficiently restrain the occupant by the high internalpressure.

As explained above, also according to the side airbag device 300, it isalso possible that the choice of the presence or absence of thedischarge of the gas is performed according to the various conditionssuch as according to the various conditions such as the collision speed,the collision angle, the physique of the occupant, and collision energyat the vehicle collision so as to adjust the internal pressure of thecushion 104. In particular, in the present embodiment, by providing theslit 304 to the patch 302, it is possible to discharge the gas furtherefficiently. As a result, it is possible that the occupant isefficiently restrained without the increase of the injury value for theoccupant.

Variation of Sewing Part

FIG. 5 is a diagram that exemplarily shows a variation of the sewingparts 124 a and 124 b shown in, for example, FIG. 2B. Sewing parts 400 aand 400 b shown in FIG. 5 are different from the sewing parts 124 a and124 b shown in, for example, FIG. 2B with respect to the providedposition.

The sewing parts 400 a and 400 b connect both-side parts of the cushion104 in the vehicle vertical direction sandwiching the vent hole 116 tothe patch 122 by sewing. The sewing parts 400 a and 400 b are alsolinearly provided in parallel with each other. As explained above, inthe same manner as the sewing parts 400 a and 400 b and the sewing parts124 a and 124 b shown in, for example, FIG. 2B, each of the sewing partscan be suitably provided at both-side parts in each directionsandwiching the vent hole 116.

Further, two sewing parts do not need to be always provided in parallel,and also do not need to be linear provided. When the patch 122 is pulledby the tether 126, the sewing part may have the configuration in which agap through which the gas passes can be formed between the patch 122 andthe vent hole 116, for instance, it is also possible that the sewingpart is formed in a curved shape along the vent hole 116.

Although the preferred embodiments of the present invention have beendescribed with reference to the attached drawings, the above-describedembodiments are preferred examples of the present invention, and otherembodiments can also be carried out in various ways. Unless there is alimited description in the specification, the present invention shouldnot be limited to the detailed shape, size, configuration, andarrangement of parts shown in the attached drawings. Further, theexpressions and terms used in the specification are for illustrativepurposes, and unless there is a limited description, the same are notlimited thereto.

Accordingly, it will be apparent to one of ordinary skill in the art toconceive various modifications within the scope of the claims. All suchmodifications are intended to be included within the technical scope ofthe present invention. For instance, in the present invention mentionedabove, in the side airbag device 100, the cushion 104 can be providedeither at the near side or at the far side of the seat back 108 in thevehicle. However, in addition to the above descriptions, it is alsopossible that the side airbag device according to the present inventionis used to a single-seated vehicle seat, for instance, such as a smallmobility.

INDUSTRIAL APPLICABILITY OF THE INVENTION

The present invention can be utilized to a side airbag device that hasan inflator that supplies a gas and an airbag cushion that is providedat a side part of a vehicle seat and that is expandable from the sidepart to a vehicle front side by the gas.

What is claimed is:
 1. A side airbag device comprising: an inflator forsupplying a gas; an airbag cushion disposed at a side of a seat of avehicle and expandable from the side in a forward direction of thevehicle by the gas; a vent hole at in the airbag cushion proximate afront side of the airbag cushion for discharging the gas from the airbagcushion; a patch that openably covers the vent hole from an inside ofthe airbag cushion; a tether connected to the patch and to apredetermined position of the side of the seat, the tether normallyoperative to open the vent hole when the airbag cushion is expanded anddeployed; and a tether cutter for cutting the tether in response toinformation relating to a state of the vehicle, wherein the patch islocated proximate a front side of the airbag and the tether cutter islocated proximate a rear side of the airbag, and further wherein thepatch is movable from an open position for venting gas through the venthole to a closed position preventing gas from venting through the venthole in response to cutting of the tether.
 2. The side airbag deviceaccording to claim 1, further comprising: sewing parts in which thepatch and first and second side areas of the airbag cushion thatsandwich the vent hole are connected by sewing.
 3. The side airbagdevice according to claim 2, wherein the sewing parts are linearlyprovided in parallel with each other at the first and second side areasof the airbag cushion that sandwich the vent hole.
 4. The side airbagdevice according to claim 1, wherein the vent hole is provided in anedge of a vehicle front side of the airbag cushion.
 5. The side airbagdevice according to claim 1, wherein the vent hole is provided in a sidesurface of the airbag cushion in a vehicle width direction.
 6. The sideairbag device according to claim 5, wherein an intermediate portion ofthe tether in a longitudinal direction is connected to the patch, and afront end of the tether is connected to an inner position of the airbagcushion, and the inner position is located further to a vehicle frontside than the vent hole.
 7. The side airbag device according to claim 5,wherein the patch has a slit that extends in a direction crossing alongitudinal direction of the tether.
 8. The side airbag deviceaccording to claim 7, wherein the tether passes through the patch viathe slit in a vehicle front direction and a vehicle rear direction. 9.The side airbag device according to claim 1, wherein the tether isconnected to the patch at a center of the vent hole.
 10. The side airbagdevice according to claim 9, wherein the airbag cushion has an outerperipheral sewing part in which a base cloth at an edge of the airbagcushion is sewed, and one end of the patch and one end of the tether aresewed together with the outer peripheral sewing part.
 11. The sideairbag device according to claim 1, wherein the inflator is disposedinside of the airbag cushion at a vehicle rear side, the side airbagdevice further including: an inner bag that is provided inside of theairbag cushion, a base cloth of the inner bag surrounds the inflator;and an inner vent that is disposed at the front side of the inner bagand through which the gas is passable, and wherein the tether passesthrough the inner vent so as to be connected to the patch and thepredetermined position of the side of the seat.
 12. The side airbagdevice according to claim 11, wherein the inner vent is located on alinear line connecting between the patch and the predetermined positionof the side of the seat.
 13. The side airbag device according to claim1, wherein the patch is attached to inner surfaces of the airbag atlaterally opposite sides of the airbag.
 14. A side airbag devicecomprising: an inflator for supplying a gas; an airbag cushion disposedat a side of a seat of a vehicle and expandable from the side in aforward direction of the vehicle by the gas; a vent hole at in theairbag cushion proximate a front side of the airbag cushion fordischarging the gas from the airbag cushion; a patch that openablycovers the vent hole from an inside of the airbag cushion; a tetherconnected to the patch and to a predetermined position of the side ofthe seat, the tether normally operative to open the vent hole when theairbag cushion is expanded and deployed; and a tether cutter for cuttingthe tether in response to information relating to a state of thevehicle, wherein an intermediate portion of the tether in a longitudinaldirection is connected to the patch, and a front end of the tether isconnected to an inner position of the airbag cushion, and the innerposition is located further to a vehicle front side than the vent hole.15. The side airbag device according to claim 14, wherein the vent holeis provided in a side surface of the airbag cushion in a vehicle widthdirection.
 16. A side airbag device comprising: an inflator forsupplying a gas; an airbag cushion disposed at a side of a seat of avehicle and expandable from the side in a forward direction of thevehicle by the gas; a vent hole at in the airbag cushion proximate afront side of the airbag cushion for discharging the gas from the airbagcushion; a patch that openably covers the vent hole from an inside ofthe airbag cushion; a tether connected to the patch and to apredetermined position of the side of the seat, the tether normallyoperative to open the vent hole when the airbag cushion is expanded anddeployed; and a tether cutter for cutting the tether in response toinformation relating to a state of the vehicle, wherein the airbagcushion has an outer peripheral sewing part in which a base cloth at anedge of the airbag cushion is sewed, and one end of the patch and oneend of the tether are sewed together with the outer peripheral sewingpart.
 17. The side airbag device according to claim 16, wherein thetether is connected to the patch at a center of the vent hole.
 18. Aside airbag device comprising: an inflator for supplying a gas; anairbag cushion disposed at a side of a seat of a vehicle and expandablefrom the side in a forward direction of the vehicle by the gas; a venthole at in the airbag cushion proximate a front side of the airbagcushion for discharging the gas from the airbag cushion; a patch thatopenably covers the vent hole from an inside of the airbag cushion; atether connected to the patch and to a predetermined position of theside of the seat, the tether normally operative to open the vent holewhen the airbag cushion is expanded and deployed; and a tether cutterfor cutting the tether in response to information relating to a state ofthe vehicle, wherein the patch has a slit that extends in a directioncrossing a longitudinal direction of the tether.
 19. The side airbagdevice according to claim 18, wherein the vent hole is provided in aside surface of the airbag cushion in a vehicle width direction.
 20. Theside airbag device according to claim 18, wherein the tether passesthrough the patch via the slit in a vehicle front direction and avehicle rear direction.